What is SaaS? Why the World Moved from Discs to Subscriptions

​1. The Old Way vs. The New Way ​In the old days, if you wanted a computer program, you went to a store, bought a physical disc, and installed it. If the company made a better version, you had to buy a new disc. ​SaaS (Software as a Service) changed everything. Now, the software lives on the internet (the Cloud), and you "rent" it every month. ​2. Why Companies Love SaaS ​No Installation: You just log in through your web browser (like Chrome). ​Always New: When the company fixes a bug, it updates for everyone instantly. You never have to "update" manually. ​Pay as You Go: Instead of paying $500 once, you pay $10 a month. This makes it easier for small businesses to start. ​3. Examples You Already Use ​Entertainment: Netflix and Spotify. ​Work: Google Docs and Microsoft 365. ​Business: Shopify (which you used for your brand) and Slack. ​4. The Technical Side: The "Multi-Tenant" Brain ​As an engineer, the coolest part of SaaS is Multi-tenancy. Imagine a giant apartment building. The buil